bundles/org.simantics.db.impl/src/org/simantics/db/impl/graph/PossibleObjectProcedure.java

   1 package org.simantics.db.impl.graph;
   2
   3 import org.simantics.db.Resource;
   4 import org.simantics.db.exception.DatabaseException;
   5 import org.simantics.db.exception.NoSingleResultException;
   6 import org.simantics.db.impl.query.IntProcedure;
   7 import org.simantics.db.impl.query.QueryProcessor;
   8
   9 public class PossibleObjectProcedure implements IntProcedure {
  10
  11         private static DatabaseException DUMMY = new DatabaseException();
  12
  13         final private QueryProcessor processor;
  14         private DatabaseException exception;
  15         private Resource result;
  16
  17         public PossibleObjectProcedure(QueryProcessor processor) {
  18                 this.processor = processor;
  19         }
  20
  21         @Override
  22         public void execute(ReadGraphImpl graph, int i) {
  23                 Resource resource = processor.querySupport.getResource(i);
  24                 if(result != null) {
  25                         exception = DUMMY;
  26                 } else {
  27                         result = resource;
  28                 }
  29         }
  30
  31         @Override
  32         public void finished(ReadGraphImpl graph) {
  33         }
  34
  35         @Override
  36         public void exception(ReadGraphImpl graph, Throwable throwable) {
  37                 if(throwable instanceof DatabaseException) exception = (DatabaseException)throwable;
  38                 else throwable = new DatabaseException(throwable);
  39         }
  40
  41         public Resource get() throws DatabaseException {
  42                 if(exception == DUMMY) return null;
  43                 else if(exception != null) throw exception;
  44                 else return result;
  45         }
  46
  47 }